This invention relates generally to display devices, and more particularly to detecting in-band tear detection while displaying video on display devices.
Latency can be a serious problem for virtual reality (VR) systems. Latency is perceived by the brain in a virtual reality (VR) environment, at best, as misaligned with expectations and, at worst, disorienting and potentially nauseating or dizzying. If latency exists in the presentation of a VR environment responsive to user-generated head motion and position data, the presented VR environment appears to “drag” behind a user's actual motion or may become choppy or non-responsive to user movement. Accordingly, latency is generally reduced to improve user experience in a VR environment.
Reducing latency can cause an increased risk of causing screen tears in the displayed video. A screen tear occurs when the rendered video being displayed includes data from two separate video frames instead of only one video frame. Conventionally, a probability of the occurrence of screen tear is controlled by separating a video frame buffer that is being scanned from the video frame buffer that is being refreshed with new data. To reduce latency, the same frame buffer that is being refreshed with new data can also be scanned soon after the frame buffer is refreshed with new data. Scanning of the video frame data increases a chance of the occurrence of a screen tear and also makes the detection of such screen tear important.